This approach uses Bootstrap's own offset classes so it requires no change in markup and no extra CSS. The key is to set an offset equal to half of the remaining size of the row. So for example, a column of size 2 would be centered by adding an offset of 5, that's (12-2)/2.

Paypal buttons don't work on aspx pages with a master page usually b/c of the embedded form tags. You can't have a form within a form.

Quick fix hack alert - Before the paypal code enter a closing form tag (This will close the asp pages form) then remove the closing form tag from the paypal code and allow the end of .net page end form tag to close the paypals form.